Hamiltonian period lattice
= Hamiltonian period lattice
{c}
{title2=$\Lambda=\{t:\varphi^t(z)=z\}$}
For a compact connected regular level of $n$ independent <Poisson-commuting functions>, the periods of their joint flow form a full-rank discrete subgroup $\Lambda\subset\mathbb R^n$. The level is $\mathbb R^n/\Lambda$. A local smooth basis of these periods determines <action integrals> and the normalized periodic fields used to construct <action-angle variables>.